Move configuration to new YGConfig and pass them down to CalculateLayout

Summary:
Move configuration to new ```YGConfig``` and pass them down to CalculateLayout. See #418 .

Adds ```YGConfigNew()``` + ```YGConfigFree```, and changed ```YGSetExperimentalFeatureEnabled``` to use the config.

New function for calculation is ```YGNodeCalculateLayoutWithConfig```.
Closes https://github.com/facebook/yoga/pull/432

Reviewed By: astreet

Differential Revision: D4611359

Pulled By: emilsjolander

fbshipit-source-id: a1332f0e1b21cec02129dd021ee57408449e10b0

javascript/sources/Config.hh

@@ -0,0 +1,49 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#pragma once
+
+#include <nbind/api.h>
+#include <nbind/BindDefiner.h>
+#include <yoga/Yoga.h>
+
+class Config {
+private:
+  YGConfigRef m_config;
+
+  Config(void)
+  : m_config(YGConfigNew())
+  {}
+
+public:
+
+  static Config * create(void)
+  {
+    return new Config();
+  }
+
+  static void destroy(Config * config)
+  {
+    delete config;
+  }
+
+  ~Config(void)
+  {
+    YGConfigFree(m_config);
+  }
+
+  void setExperimentalFeatureEnabled(int feature, bool enabled)
+  {
+    YGConfigSetExperimentalFeatureEnabled(m_config, static_cast<YGExperimentalFeature>(feature), enabled);
+  }
+
+  Config(Config const &) = delete;
+
+  Config const & operator=(Config const &) = delete;
+};